White cell and platelet trapping in patients with chronic venous insufficiency.

The cause of venous ulceration remains unclear but recent evidence suggests that white cell trapping may play a significant role. In this study venous blood taken from the dependent leg of 15 normal subjects was compared to samples taken from a similar number of patients with deep venous insufficiency. About 25 p. cent fewer white cells and platelets left the dependent foot of the patients with venous hypertension. When the foot was elevated there was a significant washout of white cells but not platelets suggesting platelet consumption within the microcirculation of the dependent foot. In 8 of the patients these changes were reversed by external compression.